spi: spi-mem: export spi_mem_default_supports_op()

Controllers can use this function to perform basic sanity checking on
the spi-mem op.

Reviewed-by: Sean Anderson <seanga2@gmail.com>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/include/spi-mem.h b/include/spi-mem.h
index fe249f7..de3c11c 100644
--- a/include/spi-mem.h
+++ b/include/spi-mem.h
@@ -250,6 +250,9 @@
 
 bool spi_mem_supports_op(struct spi_slave *slave, const struct spi_mem_op *op);
 
+bool spi_mem_default_supports_op(struct spi_slave *slave,
+				 const struct spi_mem_op *op);
+
 int spi_mem_exec_op(struct spi_slave *slave, const struct spi_mem_op *op);
 
 bool spi_mem_default_supports_op(struct spi_slave *mem,